Dishwashing machine

ABSTRACT

A dishwashing machine includes a dish loading station, a washing station and an unloading station. The washing zone is enclosed by a structure containing ingress and egress openings on both sides thereof for transfer of dishes into and out of the washing station. The loading and unloading stations flank either side of the washing station and contain transport racks for moving dishes in and out of the washing station. Each of the transport racks can function to either load or unload the washing station. A wash rack in the washing station functions to receive the dishes from either of the transport racks and to hold the dishes during the washing cycles. Thereafter the wash rack can transfer the dishes back to either of the transport racks for removal from the washing zone. Roller curtains are provided to cover and uncover the ingress and egress openings and are operative conjunctively with the wash rack to close the openings as the wash rack receives the dishes from the transport racks. Oscillating spray apparatus is mounted in the washing station. Mutually opposing manifolds are mounted in both the upper and lower portions of the washing station. The manifolds carry oscillatable spray bars which are relesably secured in the manifolds so that they can be removed for cleaning or maintenance. Holding tanks for wash and rinse water are located below the washing station. A novel rotary valve is connected to the holding tanks to selectively supply wash or rinse water to the spray apparatus through a water pump. A drain conduit and a movable diverter mechanism connected thereto can selectively direct water from the washing station to one of the wash water holding tank, the rinse water holding tank or to a drain tank.

United States Patent 1191 Wright 1 1 DISHWASHING MACHINE Kenneth F. A. Wright, 1030 W. 49th, Vancouver, British Columbia, Canada 221 Filed: Sept. 14,1973

2| Appl. No.: 397,289

[76] Inventor:

[52] US. Cl. 137/571; 134/58 D; 137/625.46 [51] Int. Cl B08b 3/00; F16k 11/02 [53] Field of Search 134/58, 83, 143, 181, 260;

[56] References Cited UNlTED STATES PATENTS 3,195,726 7/1965 Saurenman et al. 137/625.46 UX 3,530,867 9/1970 Wright 134/58 D 3,636,981 1/1972 Henry ICU/625.46

Primary ExaminerHenry T. Klinksiek Attorney, Agent, or FirmChristensen, OConnor, Garrison & Havelka [57] ABSTRACT [451 May 20, 1975 the washing station and contain transport racks for moving dishes in and out of the washing station. Each of the transport racks can function to either load or unload the washing station. A wash rack in the washing station functions to receive the dishes from either of the transport racks and to hold the dishes during the washing cycles. Thereafter the wash rack can transfer the dishes back to either of the transport racks for removal from the washing zone. Roller curtains are provided to cover and uncover the ingress and egress openings and are operative conjunctively with the wash rack to close the openings as the wash rack receives the dishes from the transport racks.

Oscillating spray apparatus is mounted in the washing station. Mutually opposing manifolds are mounted in both the upper and lower portions of the washing station. The manifolds carry oscillatable spray bars which are relesably secured in the manifolds so that they can be removed for cleaning or maintenance.

Holding tanks for wash and rinse water are located below the washing station. A novel rotary valve is connected to the holding tanks to selectively supply wash or rinse water to the spray apparatus through a water pump. A drain conduit and a movable diverter mechanism connected thereto can selectively direct water from the washing station to one of the wash water holding tank, the rinse water holding tank or to a drain tank.

14 Claims, 16 Drawing Figures PATENTEUmzo ms 3.884.263

"' saw 10$ 5 PATENTEUEM 20 I975 SHEET BF 5 PATENTED MY 2 0 I975 SHiiEi 5 OF 5 DISHWASHING MACHINE BACKGROUND OF THE INVENTION This invention relates to apparatus for washing and sterilizing glasses and dishware and more particularly to portions of a machine for automatically washing and sterilizing glasses in commercial installations such as restaurants or the like.

One object of the present invention is to provide. in a washing and sterilizing machine which has a loading station. an unloading station. and a washing station. improved mechanism for selectively transporting glasses and the like between two or more of the stations and to provide such mechanism which is simpler in construction and actuation and is more efficient than similar mechanism available in the prior art A second object of the invention is to provide a washing station which is enclosed during a washing cycle and which has side walls which can be raised and lowcred responsive to actuation and movement of the transport mechanism. thereby allowing passage of glasses and the like from the loading and unloading station into and out of the washing station.

A third object ofthe invention is to provide improved mechanism for directing a spray of wash or rinse water at glasses or the like in a washing station. to provide improved mechanism for oscillating the spray mechanism in order to more completely contact glasses or the like with water during a washing and rinsing operation. and to provide such mechanism which can be easily dismantled for cleaning or repair.

A fourth object of the invention is to provide iinproved means for storing. reusing and replenishing the wash and rinse water used in the washing machine. to provide improved means for draining water from the washing and rinsing station during operation. to provide means for conserving energy and water used by the machine. and to provide improved means for holding the wash and rinse water in the machine and redirecting it for use in the washing and rinsing operation.

A fifth object of the invention is to provide a novel valve and particularly to provide novel valve structure for interconnection with two liquid holding tanks and to further provide a mechanism for connection with such a valve for delivering wash and rinse water to the washing station.

SUMMARY OF THE lNVENTlON The foregoing objects. and other objects which will become apparent upon reading the following specifica' tion. are fulfilled by the following aspects of the invention.

In one aspect the present invention provides a transport apparatus in a dishwashing machine having a loading zone. a washing zone. and an unloading zone. which apparatus comprises first and second racks each having a frame and a plurality of elongate members mounted on the frame. The elongate members are arranged in mutually parallel relationship and are spaced from each other in a transverse direction to form respectively first and second composite dish supporting surfaces. The elongate members of the second racl-t are arranged in parallel relationship with the elongate members of the first rack. A first means is provided for reciprocating the first dish supporting surface in a vertical direction between a lowered position wherein the surface is horizontally disposed relative to the machine and a raised position superposing the lowered position. A second means is provided for reciprocating the second dish supporting surface in a lengthwise direction relative to the elongate members. The second surface is reciprocable between a first position in the washing zone wherein it is disposed in substantially parallel. stacked relationship with the first surface and a second position in the loading and unloading zone wherein it is displaced in a lengthwise direction relative to the first position. The elongate members of the first and second racks are arranged so that. when the second surface is in the first position. the respective elongate members on the first and second racks can interdigitate as the first surface is reciprocated between the lowered and raised positions. thereby allowing the first surface to superposc the second surface when the former is in the raised position to elevate dishes from the second rack and retain them in the loading zone while the second rack is returned to the loading zone. A third rack constructed similarly to the second rack. but mounted on the opposite side of the first rack from the second rack can be employed to increase the flexibility of the machine by providing separate loading and unloading zones.

A second aspect of the invention provides an improved apparatus for transporting dishes to and from a washing zone which cooperates with a door means for covering an ingress and egress opening in structure enclosing the washing zone. The apparatus includes a first door means mounted on the structure and so con structed and oriented relative to the opening as to be lowered to cover the opening and to be raised to uncover the opening. a first transport means having a dish supporting surface for carrying dishes to and from the washing zone through the opening. a dish supporting rack mounted in the washing zone. first means for sup porting the rack for reciprocating movement in a vertical direction relative to the machine between a lowered position wherein the transport means can enter the washing zone in superposed relation to the rack and a raised position wherein the rack can reciprocate relative to the transport means to elevate dishes above the dish supporting surface thereby allowing the latter to be moved from the washing zone. and actuating means coupled to the door means and to the rack and so asso ciated therewith as to raise the door means when the rack is in a lowered position to allow ingress and egress ofthe transport means and to lower the door when the rack is in a raised position. In one form the door means is a roller curtain mechanism which is lowered and raised on a reversibly rotatable shaft mounted on the housing structure above the opening. The actuating means is a mechanical linkage which converts the rotary motion used to roll and unroll the curtain into linear motion for raising and lowering the rack.

A third aspect of the invention provides water spray apparatus incorporated into the structure enclosing the washing zone in a dishwashing machine. The apparatus includes first and second manifolds spaced from each other and mounted in mutually opposing relationship in the upper portion of the structurev The manifolds have mutually opposing faces each containing a plurality of apertures. which are arranged in aligned pairs on opposing faces of the manifolds. Third and fourth manifolds are also spaced from each other and mounted in mutually opposing relationship in the lower portion of the structure. These manifolds also have mutually op posing faces each containing a plurality of apertures. which are arranged in aligned pairs on opposing faces of the manifolds. A plurality of spray bars each having ends extend between mutually opposing manifolds. The ends of the bars are rotatably mounted so that the ends of the spray bars lie adjacent respective ones of said aligned pairs of apertures. Each of the spray bars have flow channels therein communicating with the manifolds through the apertures and have a plurality of nozzle means thereon communicating with said channel. The nozzle means on the spray bars are mounted on the first and second manifolds for directing a spray of water downwardly across the washing zone. while the nozzle means on the spray bars mounted on the third and fourth manifolds for directing a spray of water upwardly across the washing zone. Drive means are provided for oscillating the spray bars to cover the washing zone with a plurality of sprays of water from the nozzle means.

Related to the third aspect means are also provided for mounting at least one of the mutually opposing manifolds for movement toward and away from the opposing manifold in a longitudinal direction relative to the spray bars. The spray bars are mounted for translation between a first position at a first spaced distance from the opposing manifold and a second position at a second greater spaced distance from the opposing manifold. The spray bars are slidable mounted in collar means surrounding the apertures and have a length in termediate the first and second distances so that, as the one manifold is moved away from the second manifold, the spray bars are released from the collar means.

A fourth aspect of the invention provides water holding and supply apparatus including a first tank means for holding wash water which is located below the washing zone, a second tank means for holding rinse water which is located below the washing zone, and a drain means associated with the first and second tank means, which is also located below the washing zone. A first conduit means connects the first and second tank means with the washing zone. A valve means is placed in the conduit means and is selectively operable to place the conduit means in fluid communication with one or the other of said tank means. A second conduit means is operatively coupled to the washing zone for draining the washing zone of water supplied thereto. Mechanism is operatively coupled to the second conduit means for selectively directing the water from the washing zone to only one of the first tank means. the second tank means, or the drain means. depending on what cycle the dishwashing machine is operating in.

In a fifth aspect the invention provides a novel rotary valve comprising first and second tubular members. In a preferred form the first tubular member has inner and outer surfaces and first and second apertures at longitudinally spaced locations along the wall thereof. The second tubular member has inner and outer surfaces and has a smaller outside diameter than the first tubular member and is mounted for rotation within the first tubular member. The second member has third and fourth apertures in the wall thereof, which apertures are spaced longitudinally from each other at a distance approximating the longitudinal separation of the first and second apertures and are angularly offset from each other in a circumferential direction relative to the second tubular member. The inner surface of the second member defines an interior channel in the second member. One end of the second member is closed while the other end is capable of functioning as an outlet. As the valve is rotated between first and second positions, the interior channel of the second member is placed in selective fluid communication with either the first or second apertures. The first and second apertures can be connected to different holding tanks to place the tanks in selective fluid communication with the valve outlet.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the present invention can be derived by reading the ensuing specification in conjunction with the accompanying drawings wherein:

FIG. 1 is an isometric view of a dishwashing machine with certain portions thereof broken away to better show the structural relationship of the components forming a part of the present invention;

FIG. 2 is an isometric view schematically showing the dish transfer mechanism, including transport racks, curtains and actuating means therefor, for transporting glasses and the like into and out of the washing station;

FIG. 3 is a cross-sectional view of a portion of a rack constructed in accord with a preferred embodiment;

FIG. 4 is an isometric view isolating the center rack of the transfer mechanism and the curtains which form movable sidewalls of the washing station and the cooperative actuating mechanism therefor;

FIG. 5 is an isometric view showing a preferred rack supporting arm which can be used in conjunction with the linkage mechanism shown in FIG. 4;

FIGS. 6, 7 and 8 are schematic elevation views show ing the components of the transfer mechanism and the sequential positions of these components during one cycle of operation wherein glasses are moved from a loading zone to the washing zone;

FIG. 9 is an isometric view isolating the spray bars and supply manifolds therefor as well as the mechanism for oscillating the spray bars;

FIG. 10 is an end view in partial section of the apparatus shown in FIG. 9;

FIG. 11 is a longitudinal sectional view taken through one of the upper spray bars and its supporting manifolds;

FIG. 12 is an exploded and enlarged isometric view of the end of a spray bar separated from a manifold to show the removable interconnection thereof;

FIG. 13 is an isometric view of the wash and rinse holding tanks and the drain tank, the selectively positionable drain mechanism for the washing station, and the novel valve for selectively supplying water from the tanks to the spray pump;

FIG. I4 is a simplified plan view showing the various positions of the selectively positionable drain mechanism illustrated in FIG. 13;

FIG. 15 is a partially broken away, side elevation view in partial section of the novel valve mechanism used to selectively supply water from the holding tanks to the spray pump;

FIG. 16 is a cross-sectional view of the valve taken along section line l6l6 of FIG. l5.

DESCRIPTION OF THE PREFERRED EMBODIMENT The dishwashing machine generally designated 20 is housed in a cabinet 22 generally having the shape of a rectangular polyhedron. The cabinet has a floor 24. a rear wall, opposing sidewalls 26 and a front wall 28 containing sliding doors 30 and a control panel 32. The cabinet is supported for movement across the floor on four castors 34. A smaller housing 36, positioned on the central top portion of the cabinet and also having the shape of a rectangular polyhedron. encloses the washing station (or zone) 38 of the machine. Loading and unloading stations (or zones) 40 and 42 are located on both sides of the washing zone. Either of these stations can be utilized. as will be further explained below. as a loading and/or unloading station. Three sinks 44, 46 and 48 are positioned in the top opening in the cabinet, are affixed to the top peripheral frame member and are recessed below the top level of the cabinet 22. The sinks 44. 46 and 48 are positioned to underlie the washing zone 38 and the loading and unloading Zones 40 and 42, respectively. The central sink collects and drains water supplied to the washing zone while the two side sinks drain the loading the unloading zones.

Translatable transport racks 50 and 52 are mounted in the top portion of the cabinet in each ofthe unloading and loading zones. The racks are mounted on rails 54 and 56. located above the sinks. The rails are transverscly extending flanges formed in the loading and unloading zones from the top. longitudinal. peripheral frame members of the cabinet. Floating rails connected to the supporting structure of the central rack support the inner ends of the side transport racks for traverse in and out of the washing zone. The rails support the racks for reciprocation into and out of the washing zone 38 to transport dishes to and from the loading and unloading zones 40 and 42. A central rack 58 located in the washing zone picks up dishes from the transport racks 50 and 52 and supports them in the washing zone during a washing and rinsing cycle.

Drive mechanism 57 for powering the transport racks in and out of the washing zone is supported by an interior platform 59 located within the right hand portion of the cabinet 22. A removable access panel is provided on the right sidewall 26 ofthe cabinet for maintenance of this drive mechanism as well as for access to the control circuitry behind the control panel and other drive mechanism utilized in the apparatus.

The housing 36 enclosing the washing zone 38 is bounded by forward wall 60. rear wall 62 and the top wall 64. The sides of the housing contain large openings 66 and 68 through which the transport racks 5t) and 52 and dishes carried thereby can be transported into and out of the washing zone. Doors in the form of roller curtains 70 and 72 are provided to cover and uncover these openings to accommodate ingress and egress of dishes into and out of the washing zone while completely closing off the washing zone during a wash and rinse cycle. These curtains are operated in conjunction with the up and down movement oftbe central rack 58. The forward wall has spaced inner and outer walls to define a cavity which holds drive mechanism for the curtains and cooperating linkage 74. A spray bar mechanism 78 which supplies an oscillating spray of wash and rinse water to the washing zone 38 is also enclosed by the housing 36. This mechanism is described in greater detail below.

The control panel 32 located on the front wall of the dishwashing machine holds on-off switches. washing cycle selection switches. and transfer cycle selection switches as ell as indicator lights for several different modes of operating the machine. Located to the left of the control panel the sliding doors 30 allow access to the interior of the dishwashing machine. Holding tanks 80 for wash water and rinse water are mounted on a movable support 82 above the floor 24 of the cabinet. The support is mounted on telescoping cantilevered rails 84 of the type used to support sliding drawers in filing cabinets, which rails are in turn mounted on the central portion of the floor 24. So mounting the platform allows the holding tanks 80 to be pulled outwardly through the doors 30 to a position in front of the cabinet for cleaning and maintenance. A wash and rinse water pump 240 for supplying water to the spray bar mechanism is also mounted on the platform for easy access. maintenance and removability. Drain conduits for the loading and unloading zone sinks 46 and 48 and from the washing zone sink 44 are located within the cabinet above the stowed position of the holding tanks 80. As will be explained in detail below. the drain conduit from the washing zone is specially adapted to operate conjunctively with the holding tanks 80 to conserve water and energy to efficiently clean and wash glasses and dishware.

Referring to FIGS. 2 and 4. the dish transfer mechanism includes the center rack 58 reciprocable in a vertical direction. a right rack 52 reciprocable to a posi tion in stacked relationship with the center rack. and a left rack 50 reciprocable in the opposite direction to the right rack to a position in stacked relationship with the center rack. Both the right and left racks are mounted to reciprocate from a position in the loading and unloading zones 40 and 42. longitudinally displaced relative to the center rack. to a position in the washing zone 38. The left and right racks are reciprocated by means ofendless flexible members 86 and 88. such as a belt or a chain. trained about a plurality of pulleys 90 and 92 driven by drive sheaves 94 and 96 connected to drive motors 98 and 100. The endless flexible members are arranged so that the upper span is parallel to the reciprocation direction of the transport racks. The flexible members 86 and 88 are fixed respectively to arms 102 and 104 which in turn extend perpendicularly downwardly from the respective racks 52 and 50. As the reversible motors rotate the drive sheaves 94 and 96 the upper spans of the flexible members translate in turn powering the racks for movement along their mounting rails. The center rack 58 is powered for up and down movement in a vertical direction within the washing zone 38 by the support mechanism 76. explained below in conjunction with the curtain operating mechanism.

The construction of the left and right transport racks is identical and will be explained in conjunction only with the right rack 52. Transverse frame members 106 and 108 are positioned in a transverse orientation relative to the longitudinal dimension of the dishwashing machine. The transverse frame members are intercom nected by a plurality of elongate members 110 which are spaced from and parallel to each other. and run lengthwise relative to the dishwashing machine. The transverse frame members and the elongate members together form a rack or grate structure which provides a composite dish supporting surface. The transverse frame members are supported for movement into and out of the washing zone by rails (shown in FIG. 1).

The central rack 58 is also composed of transversely arranged frame members H2 and 114 which are spaced in parallel relationship from each other. These transverse frame members 112 and 114 are also inter connected by a plurality of elongate members 116 which are spaced from each other and parallel to each other as well as being parallel to the elongate members 110 of the right rack 52. The elongate members 110 of the right rack are arranged in alternating relationship relative to the elongate members 116 of the central rack such that as the right rack is moved from the loading and unloading zone into the washing zone. the elon gate members interdigitate. Vertical slots 118 are formed in the transverse frame members 112 and 114 between the elongate members 116 of the center rack to receive the elongate members 110 of the transport racks.

A preferred construction and interconnection for the transverse and elongate members of the center rack is shown in FIG. 3. The left transverse frame member 112' is a three flanged channel member. It has a lower flange 122. a central flange 124 and an upper flange 126. The web 129 of the channel is vertically oriented while the flanges extend perpendicularly to the web. The right transverse member (not shown) is a mirror image of the left. The rod-like elongate member 116' is constructed from a steel rod which has its side portion 128 bent downwardly at a right angle to the portion ofthe member which forms a part of the composite dish supporting surface. Vertically aligned holes 130 and 132 are provided in the upper and central flanges. The bottom end of the side portion 128 of the elongate member extends downwardly through these holes and rests on the upper face of the lower flange 122. Rigid elongate members 116 are affixed to and extend longitudinally between the forward ends of the transverse members and between the rearward ends of the transverse members. The center rack is supported through these forward and rearward elongate members by the rocker arms (described below) forming part of the support structure for the center rack. By using this con struction the elongate members can be easily removed for cleaning and access to the sink in the washing zone. The spaces between the upright end portions 128 correspond to the slots 118 (FIG. 2) to provide separation for intcrdigitation of the elongate members on the side racks.

Referring back to FIGS. 2 and 4. the center rack 58 is in a lowered position wherein the dish supporting surface formed by elongate members 116' of the transport rack 52 is positioned in a plane above but substantially parallel to the dish supporting surface formed by the upper edges of the elongate members 116' of the center rack. Thus. no interference by the center rack occurs as the transport rack moves into the washing zone. After the dish supporting surface of the transport rack is translated into the washing zone. the support mechanism 76 for the center is moved upwardly by actuation ofthe linkage 74. As this occurs. the elongate members 116' of the center rack move into and through in interdigitatcd relationship from a position below the elongate members 110 of the side racks to a position wherein the dish supporting surface of the center rack 58 is positioned above but substantially parallel to the dish supporting surface of the transport racks. In this manner dishes are transferred from the transport rack to the center rack prior to the initiation of a washing and rinsing cycle. At the same time the center rack is moved upwardly. the curtain walls are actuated through the chain and sprocket arrangement such that the curtains are unrolled from the shafts and gravitate downwardly to close off the side openings 66 and 68 in the housing 36 enclosing the washing zone.

The roller curtains 70 and 72 are respectively mounted on shafts 134 and 136 in turn rotatably supported in the upper portion of the housing 36 (not shown in this FIGURE) for the washing zone. Sprockets 138 and 140 are fixed to the forward ends of each shaft. Three interconnected idler sprockets generally indicated at 142, are rotatably mounted adjacent the right sprocket 140. One of the three idler sprockets is driven by a chain 144 in turn driven by a reversible electric motor 146 (shown schematically in FIG. 1). An endless chain 148 is trained over a second of the idler sprockets and the left sprocket 138 to drive the left curtain shaft. The third idler sprocket and the right shaft sprocket are driveably interconnected by meshing gears. In this manner the curtain shafts 134 and 136 are rotated in opposite directions so that the curtains can be raised or lowered as the idler sprockets are reversibly driven.

The center tray 58 is supported by four transversely extending pins mounted on four rocker arms. The two right-hand rocker arms 150 are secured to a shaft 152 mounted for rotation in the cabinet on the lower righthand side of the washing zone. Likewise, the lefthand rocker arms 154 are secured to a shaft 156 mounted for rotation on the cabinet on the lower left-hand side of the washing zone. Each of the forward rocker arms 150 and 154 has an upwardly extending arm to which the actuating linkage is connected. The transversely extending pins are mutually aligned in pairs and underlie the forwardmost and rearmost elongate members 116 interconnecting the ends of the spaced transverse frame members 112 and 114. As shown in FIG. 2 the rocker arms are supporting the center tray at the upper limit of its travel.

FIG. 5 shows an alternate embodiment for the rocker arms that support the center rack. In this embodiment the rocker arms 158 comprise a two-armed crank as shown. However, the arms are positioned with respect to each other at an acute angle. The left arm 160 is is connected to a link forming part of the actuating linkage. The right arm 162 however does not contain a transverse peg but pivotally supports an L-shaped angle member 164. The center rack shown in ghost outline rests on the transversely extending arm of the angle member 164. This embodiment does not require substantial relative motion between the arm and tray but allows most of the motion to occur in the pivot pin interconnecting the right arm and the angle member, thus reducing wear and maintenance on the appratus.

Again referring to FIGS. 2 and 4 the rocker arms 150 and 154 are rotated to raise the center rack by linkage 74 which in turn is actuated by the chain 144 trained between the left sprocket 138 and one of the idler sprockets 142. The linkage 74 includes a central bell crank 166 mounted for pivotal movement about a shaft having its axis parallel to the rocker arm shafts 152 and 156 and being secured to the cabinet 22 (not shown in this FIGURE) in the washing zone between the rocker arm shafts. A lower arm of the central bell crank 166 is connected by a link 168 to the upwardly extending arm of the left forward rocker arm 154. upper arm of the central bell crank 166 is connected by a link 170 to the upwardly extending arm of the right forward rocker arm 150. As the bell crank rotates about its pivot shaft, the two links 168 and 170 are moved in opposite directions causing the rocker arms to rotate in opposite directions, thereby raising and lowering the center rack. A third sidewardly extending arm l72 on the central bell crank is connected by a link 174 to an idler crank 176, the latter being connected to a shaft 178 located above the central bell crank. The shaft 178 is in turn connected to an upwardly extending tubular member I80. A rod member 182 extends downwardly into the tubular member and has its upper end attached to a block 184 in turn fixed to the chain 144 trained between the sprockets 138 and 142. The position of the block on the chain is adjustable so that the relative motion between the curtains and center tray can be appropriately adjusted. Thus, as the curtains are raised by moving the drive chain 148 in the direction of the arrow 186, the bottom span of the horizontal chain 144 is moved from right to left. As this occurs, the block moves from right to left cranking the tubular member from right to left. In turn the actuation of the remainder of the linkage causes the rocker arms 150 and 154 to move the center rack to the lower position as shown in FIG. 4. When the curtains are lowered, the reverse operation of the linkage occurs causing the rocker arms to move upwardly about their shafts and thus raise the center rack so that its dish supporting surface rests at a location above but substantially parallel to the dish supporting surface of the transport racks.

Referring to the sequence of operation of the transfer mechanism and curtains as shown in FIGS. 6 through 8, a plurality of glasses are loaded on the dish supporting surface of the right rack 52. The arm 102 extending downwardly from the rack is connected to the flexible member 86 trained about the several pulleys so that an upper portion of the belt lies in a plane parallel to the plane of reciprocation of the right rack. Prior to energizing the right rack drive motor 98, the linkage 74 (shown in FIGS. 2 and 4) is actuated to cause the roller curtains 70 and 72 to raise and the center rack 58 to lower so that its dish supporting surface is below the dish supporting surface of the side racks. The drive motor 98 is then energized to turn the traction sheave 94 causing the flexible member to move in a direction from right to left as indicated by the arrow 188 (FIG. 7). As the flexible member so moves, the glasses are transported into the washing zone.

The traction sheave is sized such that its circumference is equal to the reciprocation distance of the side tray from the right loading and unloading zone to the washing zone. The traction sheave 94 contains a cam surface 190 which on one revolution will contact a limit switch 192 de-energizing the drive motor 98 and stopping the tray in the washing zone. The drive motor is a reversible DC motor. As the limit switch is contacted by the cam surface 190 the polarity of the motor is reversed. Through a series of electrical relays and other conventional control circuitry, the drive motor 146 (FIG. 1) for the center tray and the curtains is actuated to drive the linkage 74, causing the dish supporting surface of the center rack 58 to rise above the dish supporting surface .of the side rack 52 while the curtains are gravitated downwardly to close the sides of the washing zone housing. After the center tray has reached the upper limit of its travel, conventional circuitry tie-energizes the linkage drive motor 146. Additional relays and conventional control circuitry responsive to the deactivation of the linkage drive then reenergizes the drive motor 98 for the right tray in a reverse direction, causing the traction sheave to rotate in the reverse direction and transporting the side rack back to the loading and unloading zone. On one revolution of the traction sheave, the cam surface again contacts the limit switch 192 de-energizing the drive motor 98 and stopping the side rack in the unloading zone. At the same time the polarity of the drive motor is again reversed through the control circuitry to prepare for another transfer cycle.

At the end of the washing cycle the dishes are removed from the washing zone by reversing the cycle described above. This cycle can be followed by viewing FIGS. 6 through 8 in the reverse order. Briefly, the transport rack 52 enters the washing zone while the center rack is in its raised position. Upon reaching the washing zone, the center rack is lowered so that its dish supporting surface is below that of the side rack. Thus, the glasses are transferred to the dish supporting surface of the side rack. As the center rack is lowered, the curtains are raised. Thereafter the side rack carries the glasses to the unloading zone on its supporting surface.

As can be seen, an identical drive mechanism is utilized to reciprocate the left rack 50 into and out of the washing zone. The operation of the left rack and drive mechanism is the mirror image of the operation of the right rack and therefore need not be explained further. However, it should be noted that the sequence of operation of the right and left racks can be arranged through convention control circuitry in such a manner that glasses loaded on the right rack and transferred to the washing zone can be removed from the washing zone by the left rack. Of course, the opposite is also true, i.e., dishes loaded on the left rack can be transferred to the washing zone and be removed by the right rack. Control circuitry for sequencing a similar manner of operation is disclosed in US. Pat. No. 3,530,864, issued Sept. 29, 1972, to Kenneth F. A. Wright.

It should also be noted that the side racks are not mounted for movement in a vertical direction but only for movement in a longitudinal direction relative to the cabinet. Likewise, the center rack cannot move in a lengthwise direction but is mounted only for up and down movement in vertical direction relative to the cabinet. This construction of the side and center racks along with the sequence of operation and the relative movement of each of the racks with respect to the other allows a substantial simplification in the operating and control mechanism, especially in the interconnecting linkage, over what has been available in the prior art. This apparatus is not only economically advantageous but also requires relatively little amount of maintenance to keep the equipment at full operation.

Referring now to FIGS. 9, l0 and ll, the spray bar mechanism 78 includes upper front and rear manifolds I94 and I96, respectively, and lower front and rear manifolds 198 and 200, respectively. The manifolds are mounted to the washing zone housing by means to be explained in greater detail below. The upper and lower rear manifolds are interconnected by a conduit 202 preferably formed integrally with the manifolds. The upper and lower manifolds are positioned in mutually opposing relationship so that the interior faces thereof are opposite each other. Each of the interior faces of the manifolds 194, 196, 198 and 200 contains a plurality of apertures which are arranged in a lengthwise array along the faces. The apertures are arranged in mutually opposing transversely aligned pairs. Each aperture is surrounded by an annular collar, which is affixed to the inner faces of the manifolds. Each pair of mutually opposing collars supports a spray bar for reversible rotation about its longitudinal axis and for translation relative to the longitudinal axis. The ends of the spray bars abut the inner faces of the manifolds adjacent the apertures.

The spray bars are constructed from tube stock. The hollow central portions of the bars place the opposing manifolds in fluid communication with each other. The upper and lower manifolds each carry five spray bars 204. A plurality of nozzles 206 are located on the upper spray bars and are oriented with respect to each other and the spray bars so that water issuing therefrom is formed into a spray and is directed generally in a downward direction.

The upper spray bars are reversibly rotated through an arc to cause the spray nozzles to oscillate to fully cover the entire washing zone. Downwardly extending arms 208 are affixed to each of the upper spray bars near the rearward end thereof. These arms are connected by pivot pins 210 to a single horizontal connecting link 212. As this link reciprocates in a left and right direction the spray bars are reversibly rotated through an arc of generally 30 to 60 degrees. In this manner the water spray issuing from the upper nozzles 206 is oscillated to cover the entire washing region from the upper side. The lower manifolds 198 and 200 also carry five spray bars 214 mounted in apertures for reversible rotation and longitudinal translation. Spray nozzles 216 are provided on the lower spray bars and are arranged to direct the spray issuing therefrom in a generally upward direction across the washing zone. Similarly to the upper spray bars, arms 218 extend downwardly from each of the plurality of spray bars and are interconnected by a second horizontal connecting link 220. As the lower link is reciprocated, the lower spray bars are reversibly rotated through an arc of from 30 to 60 so that the spray therefrom is oscillated to cover the entire washing zone from the bottom.

The mechanism 222 for oscillating the spray nozzles is located adjacent the forward wall of the housing 36 enclosing the washing zone. Each of the upper and lower righthand spray bars 204 and 214 carry transversely extending arms 224 and 226 near its forward end. The upper arm 224 is pivotally connected to a downwardly extending drive link 228 and the lower arm 226 is pivotally connected to an upwardly extending drive link 230. These two links are interconnected to a rotatable eccentric mechanism 232 which oscillates the drive links 228 and 230 upwardly and downwardly. As this occurs, the upper and lower righthand spray bars are reversibly rotated which in turn causes reversible rotation of the remainder of the upper and lower spray bars 204 and 214 through the connecting links '212 and 220. The eccentric mechanism 232 is driven by a motor 234 through the belt and pulley arrangement 236.

Referring to both FIGS. 9 and 11, the lower rear manifold 200 is supplied with wash water or rinse water through a flexible conduit 238 from a pump 240. The pump, driven by an integral electric motor 242, receives its supply of water from the holding tanks 80 (shown in FIG. 1). The water enters the lower manifold 200 and travels through the lower hollow spray bars 214. In this manner the pressure supplied to the nozzles on each of the spray bars is substantially the same since the pressure equalizes throughout the mutually opposing lower manifold. Water also travels upwardly through the conduit interconnecting the lower and upper rearward manifolds. The water travels through the upper spray bars in a manner identical to that of the lower spray bars to equalize the supply pressure to the nozzles on the upper spray bars.

Referring now to FIGS. 9, l1 and 12, the upper front manifold 194 is mounted for reciprocating movement toward and away from its mutually opposing manifold to releasably mount the spray bars in the manifolds. The upper forward manifold, which is of rectangular polyhedron configuration, is mounted for reciprocating movement on a pair of pins 244 (one of which is shown in FIGS. 11 and 12) which are in turn secured to the upper forward portion of the washing zone housing 36. A pair of mutually aligned holes are provided in the manifold at the appropriate location to receive the pins 244. A retaining nut 246 is threaded onto the inner end of each of the pins 244 to limit the inward travel of the upper front manifold toward the opposing manifold. A seal is provided in the holes through which the pins 244 extend to prevent leakage from the manifold. Leaf springs 250 interpose the forward wall of the upper front manifold and the inner wall of the washing zone housing at the location of each of the pins 244. A retaining aperture 248 (FIG. 9) is provided in the center portion of each of the springs. The pins extend through these retaining apertures to prevent the leaf spring from dropping out of its desired location. This leaf spring 250 is so constructed as to place a biasing force on the manifold so that it will normally rest at the innermost end of its travel against the nut 246.

The spray bars 204 and 214 are mounted not only for oscillation in the collars 252 mounted on the manifolds as stated above but are also slidably mounted for movement in a longitudinal direction relative to the spray bar. Each of the collars surrounding each of the apertures has an annular groove which carries an O-ring seal 254 to prevent leakage around the spray bar. Each of the collars has a thickness in its axial direction substantially the same as the distance through which the manifold can reciprocate against the leaf spring. As the manifold is moved forwardly against the compressive force of the leaf spring, the forward end of the spray bar will emerge from the opening in the collar 252. A shoulder 256 is integrally constructed with the lower part of each of the collars. A recess or groove 258 is provided in each of the shoulders. The recess aligns with the mounting hole in the collar, thus allowing the shoulder to support the spray bar to prevent it from falling downwardly when the manifold is moved against the spring. In this manner the spray bars will not fall from their mounted location when the manifold is moved. However, the spray bars can be easily removed for cleaning and maintenance by lifting upwardly on the forward end of the bars and pulling forwardly to remove the bars from the rear collar. The connection between the pivot pins 210 and the horizontal links 212 and 220 are of the quick disconnect type so that each of the spray bars can be removed individually.

Now referring to the views of FIGS. 13 and 14, the holding tank generally designated is of rectangular construction in plan view. The tank is divided into three portions by two partitions. A first divider 260 runs longitudinally about three-fourths of the length of the tank from the front wall toward the rear wall and is centered between the side walls of the tank. The rear end of the first partition is secured to the forward side of a second partition 262 which lies perpendicular to the first partition and separates the rearward onefourth of the tank from the other two portions separated by the central partition. The left forward tank 264 is a wash water holding tank and the right forward tank 266 is the rinse water holding tank The rear portion 268 of the tank is connected to a drain conduit (not shown) which in turn is connected to a sewage disposal drain.

Hot water is supplied to the wash holding tank by a first conduit 270, the flow through which is controlled by a solenoid valve 272. The solenoid valve is of standard construction and is connected to a pressure sensor 274 mounted through the wall of the wash tank near the floor of the tank. When the water level in the tank drops below a predetermined level, the pressure sensor activates the solenoid valve to fill the tank at which time the pressure sensor turns the solenoid valve off. The wash tank is normally supplied with hot water on the order of 150 to 180. In addition the water in the wash tank is maintained at about 180 during the wash cycle by conventional immersion heating element (not shown) positioned in the lower portion of the wash tank. The heating element is powered through leads connected to an appropriate electrical power source. The rinse tank 266 is supplied with cold water, normally between 45 and 50 Fv through a conduit 276. The level of water in the rinse tank is also controlled by a pressure sensor 278 which actuates and deactuates the solenoid valve 280 connected to the cold water supply conduit 276. A bleed line 282 is provided to supply some hot water to the rinse tank as the wash tank is being filled.

Two pipes 284 and 286 are respectively connected to drain openings in the bottom of the wash tank and rinse tank. These pipes are in turn connected to a novel rotary valve mechanism 288, the details of which will be described below, controlled by the rotary actuator 290 which is in turn controlled by conventional control circuitry (not shown). The rotary valve can be rotated to place one or the other of the pipes in fluid communication with the outlet of the valve. The outlet of the rotary valve is connected to a supply conduit 293 running to the spray pump. The spray pump then supplies the manifolds of the oscillating spray apparatus described above Thus, the spray pump can supply, upon demand. either wash water or rinse water, depending upon the position of the rotary valve mechanism.

Any wash water escaping from the washing zone into the side tanks underlying the right and left loading and unloading zones and any residual water on glasses after being washed and transferred to the unloading zone is drained back to the drain tank 268 through respective left and right drain pipes 292 and 294. The water from the sink underlying the washing zone drains into a conduit section 296 which is fixed to the bottom portion of the sink underlying the washing zone. The longitudinal axis of the fixed conduit section 296 is vertically oriented and substantially coincides with the intersection of the central partition 260 and rearward partition 262 in the holding tank. A rotatable bottom conduit section 298 is connected to the upper fixed section 296 through a rotatable collar mechanism 300 of conventional design. The rotatable collar section has an annular groove around which is trained a belt 302. The belt is also trained about another pulley which is connected to the output shaft of an electric motor 304. The electric motor is a reversible DC motor and is controlled both in direction and duration of running by several cam wheels 306 connected to the drive shaft and by limit switches 308 which are connected to relays and conventional control circuitry (not shown). In this embodiment the rotatable bottom conduit section has a first portion 310 which extends downwardly from the rotatable collar and has its axis substantially coincident with the axis of the upper fixed section. A lower portion 312 affixed to the first portion angles obtusely downwardly from the vertically oriented first portion. The angled section of the conduit has an outlet 314 which overlies the holding tank. As best shown in FIG. 14, the rotatable bottom section can be selectively positioned to overlie the wash holding tank 264 (reference numeral 2980), the rinse holding tank 266 (reference numeral 298b) or the drain tank 268 (reference numeral 298C). The rotatable drain pipe can thus selectively return water from the washing zone to any one of the three tanks, as best illustrated in FIG. 14.

Strainer baskets 313 of substantially conventional design are positioned in each of the three tanks to underlie the outlet of the rotatable bottom conduit 298. The strainer baskets catch any particulate material which may be washed from the dishes prior to the time the water re-enters the holding tank. Of course, the strainer baskets must be periodically cleaned between operating cycles of the machine.

FIGS. 15 and 16 illustrate the novel rotary valve mechanism 288 of the present invention. The body 316 of the valve is an elongate tubular member having a relatively thin wall. Two riser pipes 284 and 286 are fixed to the upper portion of the body and in turn are connected at their upper ends to the drain openings in the wash tank and holding tanks, respectively. The riser pipes 284 and 286 communicate with the interior of the body 316 through respective openings 318 and 320 in the upper portion of the wall of the body. A second tubular member 322 constituting the valve member is rotatably mounted within the tubular body 316. The second tubular member 322 has an outside diameter substantially equal to or slightly less than the inside diameter of the body. The tubular members can be of substantially the same length. The second tubular member is closed at its right end and is retained within the body by a disc 315 affixed to its right end. A radially exposed shoulder 317 on the disc 315 abuts the right end of the body to prevent the second tubular member from sliding to the left. A snap ring 319 disposed in an annular groove 321 running about the circumference of the second tubular member abuts the left end of the body to prevent the second tubular member from sliding to the right.

The second tubular member contains two openings 324 and 326 which are spaced longitudinally along the tubular member at the same spacing as the two openings 318 and 320 which communicate with the riser pipes. However, the openings in the second tubular member 322 are angularly offset by about In the position shown in FIGS. 15 and 16 the left hand opening 324 in the second tubular member 322 is aligned with the opening below the riser pipe 284 connected to the drain opening in the wash tank 264. Thus, wash water can flow through both openings 318 and 324 into the interior of the rotatable tubular member 322. The left end of the valve body 316 is attached to the supply conduit which leads to the spray pump. Thus, wash water can be supplied through the valve to the washing zone. At the same time, the opening 326 in the second tubular member is not aligned with the opening 320 in the body preventing flow through the riser pipe 286 connected to the rinse tank. During the appropriate rinse cycle the rotary actuator 290 connected to the right end of the second tubular member 322 via coupling arrangement 328 is rotated l80 such that the left opening 324 in the second tubular member is displaced from the corresponding opening 318 in the body. At the same time the right opening 326 in the second tubular member is rotated into alignment with the opening 326 communicating with the riser pipe connected to the rinse tank. In this manner the flow of wash water to the spray pump is cut off and is replaced by rinse water.

The coupling 328 interconnecting the actuating motor 290 and the inner valve member 322 includes a first cylindrical extension 330 affixed to and extending outwardly from the disc 315 attached to the right end of the inner tubular member. A diametral slot 332 is provided in the cylindrical member, which slot opens toward the actuating motor 290. A plate 334 is mounted on the output shaft of the motor and extends in mating relationship into the diametral slot, thereby coupling the actuating motor to the valve Regardless of which opening in the inner tubular member is positioned in communicating relationship with the respective openings in the valve body, the diametral slot 332 is positioned horizontally relative to the orientation of the internal openings in the valve and relative to the platform on which the holding tank 80 rests. Thus when the holding tank 80 is slid outwardly from the cabinet for service (as described in conjunction with FIG. 1), the cylindrical member 332 will slide off the plate 334 thereby automatically uncoupling the valve from the actuator 290.

In operation, glasses to be washed are placed on one of the left or right transport racks. The term glasses is used herein as a matter of convenience. [t is intended that when the term glasses or dishes is used that it includes all glasses, dishware and silverware. For purposes of this operational description, glasses are loaded onto the right transport rack 52 and are unloaded from the left transport rack 50. However, it is to be understood that the transport racks can be operated in any desired sequence, as described above, to load or unload glasses from either loading and unloading zone. In addition conventional dish holding baskets can be placed on the racks and transported into and out of the washing zone in the same manner as glasses placed directly on the racks.

After manually loading glasses on the right rack, the glasses are transported to the washing zone 38. The washing sequence is initiated by appropriately manipulating the transfer mechanism cycle selection dial and the wash and rinse cycle selection switches on the com trol panel 32 at the front of the cabinet 22. Thereafter, the cycle start switch is thrown which energizes the drive motor for the linkage 74 causing the side curtain 72 to raise and at the same time causing the center rack 58 to move to its lowered position. The right side transport rack 52 then enters the washing zone 38. Thereafter the center rack 58 moves to its raised position transferring the glasses to its dish supporting surface. At the same time the side curtain 72 is unrolled to a position closing the opening 66 to the washing zone. The right side rack 52 then reciprocates to its rest position in the loading zone 42.

Thereafter, through appropriate control circuitry the drive motor for the spray pump 240 is energized. The inner tubular member of the rotary valve mechanism 288 is positioned so that the conduit between the spray pump 240 and the rotary valve is in fluid communication with the wash holding tank 264, thereby supplying wash water through the pump 240 to the oscillating spray mechanism 78 in the washing zone 38. As the spray pump motor is energized, the rotatable bottom conduit 298 of the drain from the wash sink 44 is rotated to a position wherein water from the washing zone is discharged to the drain tank 268. The rotatable drain conduit remains in this position for about 12 seconds, after which it is rotated in a counterclockwise direction so that the water from the washing zone is recycled to the wash holding tank 264. During the initial 12 second period most of the dirty wash water and roughage from the dishes is drained out of the washing zone. During the next 50 seconds the wash pump continues to supply wash water to the washing zone, which water is recycled to the wash holding tank 264. Appropriate control circuitry is provided to enable the operator to vary the washing period for any desired length of wash, for example, from 50 seconds up to an additional 60 seconds. After the 50 second period, the pump motor is de-energized. The rotatable drain remains in the position over the wash holding tank for another 5 seconds to allow substantially all of the wash water to drain from the washing zone. Thereafter, the rotatable drain conduit 298 is rotated in a clockwise direction to a position over the drain tank 268.

The rinse cycle is initiated by re-energizing the spray pump motor and rotating the valve mechanism 288 to a position wherein the outlet of the rinse tank 266 is placed in communication with the spray pump and the outlet from the wash tank 264 is closed. Rinse water is thus supplied by the pump to the oscillating spray mechanism 78 in the washing zone. The rotatable drain conduit 298 remains in the position over the drain tank 268 for a period of 12 seconds after which it is rotated in a clockwise direction to a position over the rinse tank 266, recycling rinse water to the rinse holding tank 266. The spray pump continues to operate for about 50 seconds, after which the pump motor is deenergized. The outlet of the rotatable drain conduit 298 remains over the rinse tank for about 5 seconds to completely drain residual rinse water from the washing zone.

The rinse cycle is completed by rotating the drain conduit 298 to a position over the drain tank 268 and returning the rotary valve 288 to a position opening the outlet of the wash tank 264 and closing the outlet to the rinse tank 266. During the operational cycles the pres sure sensors 274 and 278 open the respective solenoid valves 272 and 280, to replenish the supply of wash and rinse water. At this juncture the machine is reset so that new washing and rinsing cycles can be initiated on demand.

Thereafter the left side transport rack 50 is moved from its rest position in the left unloading zone 40 to a position within the washing zone 38. The left roller curtain 70 is then raised by actuation of linkage 74, while the center rack 58 is reciprocated to its lowered position depositing the glasses onto the left transport rack 50. The left transport rack is then reciprocated out of the washing zone to the unloading zone 40 where the glasses can be manually removed from the rack. The roller curtains 70 and 72 remain open when the machine is not in operation to allow air to circulate naturally through the side openings 66 and 68 to aid in drying the washing zone.

Several aspects of the present invention have been discussed in detail above. Preferred embodiments of these aspects have been disclosed. It is within the ability of one of ordinary skill in the art to make various alterations to, substitutions of equivalence in, and other changes to these embodiments. it is intended, however, that the several aspects of the present invention be limited only by the definition contained in the appended claims.

What is claimed is:

1. In a dishwashing machine having a washing zone, a loading zone and an unloading zone, water holding and supply apparatus comprising:

a first tank means for holding wash water located below said washing zone,

a second tank means for holding rinse water located below said washing zone,

drain means associated with said tank means and located below said washing zone,

first conduit means for supplying water from said first and second tank means to said washing zone and valve means in said conduit means selectively operable to place said conduit means in fluid communication with one of said tank means,

second conduit means operatively coupled to said washing zone for draining said washing zone of water supplied thereto, and

means operatively coupled to said second conduit means for selectively directing said water from said washing zone to one of said first tank means, said second tank means, and said drain means.

2. The dishwashing machine of claim 1 wherein said second conduit means has an outlet and wherein said means operatively coupled to said second conduit means comprises a movable conduit member and means coupling said conduit member to said second conduit means for rotation about an axis relative thereto, said conduit member arranged to receive water from the outlet of said second conduit means, said conduit member having an outlet transversely displaced relative to said axis, means for selectively positioning said outlet over first, second and third locations, said first tank means, said second tank means and said drain means so associated respectively with said first, second and third locations to receive water from said conduit member.

3. The dishwashing machine of claim 2 wherein said tank means and said drain means comprise a tank having a top opening and at least two intersecting partitions therein for dividing said tank into at least three portions corresponding to said first tank means, said second tank means and said drain means, said conduit member being positioned over the intersection of said partitions.

4. The dishwashing machine of claim 3 further comprising:

strainer means positioned in said three portions at said three locations to separate particulate matter from water being returned from said washing zone.

5. The dishwashing machine of claim I wherein said drain means comprises:

a first tubular member having inner and outer surfaces and having first and second apertures at longitudinally spaced locations along the wall thereof,

a second tubular member having inner and outer surfaces and having a smaller outside diameter than said first tubular member and being mounted for rotation within said first tubular member, said inner surface defining an interior channel in said second tubular member, said second tubular member having third and fourth apertures in the wall thereof, said third and fourth apertures being spaced longitudinally from each other at a distance approximating the longitudinal separation of said first and second apertures and being angularly offset from each other in a circumferential direction relative to said second tubular member,

first means placing the exterior of said valve in fluid communication with said interior channel, said first and second tubular members being rotatable relative to each other between a first position wherein said first aperture is placed in fluid communication with said third aperture and at least a second position wherein said second aperture is placed in fluid communication with said fourth aperture,

third conduit means placing said first aperture in fluid communication with said first tank means,

fourth conduit means placing said second aperture in fluid communication with said second tank means, and

means for pumping fluid from said drain means to said washing zone.

6. The dishwashing machine of claim 5 further comprising:

seal means for preventing fluid leakage between said first and second apertures, said seal means being positioned between the inner surface of said first tubular member and the outer surface of said second tubular member and being positioned at least in part between said first and second apertures.

7. The dishwashing machine of claim 6 wherein said seal means comprises:

a first pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said third aperture,

a second pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said third aperture and extending between and joining with said first pair of seal members to form a continuous seal around said third aperture,

a third pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said fourth aperture, and

a fourth pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said fourth aperture and extending between and joining with said third pair of seal members to form a continuous seal around said fourth aperture.

8. The dishwashing machine of claim wherein one end of said second tubular member is closed and wherein said first means comprises an opening in the opposite end of said second tubular member.

9. The dishwashing machine of claim 8 further comprising:

drive means coupled to said one end of said second tubular member for rotating said second tubular member between said first and second positions, said first tubular member being stationary relative to said second tubular member.

10. A valve comprising:

a first tubular member having inner and outer surfaces and having first and second apertures at longitudinally spaced locations along the wall thereof,

a second tubular member having inner and outer surfaces and having a smaller outside diameter than said first tubular member and being mounted for rotation within said first tubular member, said inner surface defining an interior channel in said second tubular member, said second tubular member having third and fourth apertures in the wall thereof, said third and fourth apertures being spaced longitudinally from each other at a distance approximating the longitudinal separation of said first and second apertures and being angularly offset from each other in a circumferential direction relative to said second tubular member, and

first means placing the exterior of said valve in fluid communication with said interior channel, said first and second tubular members being rotatable relative to each between a first position wherein said first aperture is placed in fluid communication with said third aperture and at least a second position wherein said second aperture is placed in fluid communication with said fourth aperture.

11. The valve of claim 10, further comprising:

seal means for preventing fluid leakage between said first and second apertures, said seal means being positioned between the inner surface of said first tubular member and the outer surface of said second tubular member and being positioned at least in part between said first and second apertures.

12. The valve of claim 11 wherein said seal means comprises:

a first pair of seal members being positioned at least a third pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said fourth aperture and a fourth pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said fourth aperture and extending between and joining with said third pair of seal members to form a continuous seal around said fourth aperture.

13. The valve of claim 10 wherein one end of said second tubular member is closed and wherein said first means comprises an opening in the opposite end of said second tubular member.

14. The valve of claim 13 further comprising:

drive means coupled to said one end of said second tubular member for rotating said second tubular member between said first and second positions, said first tubular member being stationary relative to said second tubular member. 

1. In a dishwashing machine having a washing zone, a loading zone and an unloading zone, water holding and supply apparatus comprising: a first tank means for holding wash water located below said washing zone, a second tank means for holding rinse water located below said washing zone, drain means associated with said tank means and located below said washing zone, first conduit means for supplying water from said first and second tank means to said washing zone and valve means in said conduit means selectively operable to place said conduit means in fluid communication with one of said tank means, second conduit means operatively coupled to said washing zone for draining said washing zone of water supplied thereto, and means operatively coupled to said second conduit means for selectively directing said water from said washing zone to one of said first tank means, said second tank means, and said drain means.
 2. The dishwashing machine of claim 1 wherein said second conduit means has an outlet and wherein said means operatively coupled to said second conduit means comprises a movable conduit member and means coupling said conduit member to said second conduit means for rotation about an axis relative thereto, said conduit member arranged to receive water from the outlet of said second conduit means, said conduit member having an outlet transversely displaced relative to said axis, means for selectively positioning said outlet over first, second and third locations, said first tank means, said second tank means and said drain means so associated respectively with said first, second and third locations to receive water from said conduit member.
 3. The dishwashing machine of claim 2 wherein said tank means and said drain means comprise a tank having a top opening and at least two intersecting partitions therein for dividing said tank into at least three portions corresponding to said first tank means, said second tank means and said drain means, said conduit member being positioned over the intersection of said partitions.
 4. The dishwashing machine of claim 3 further comprising: strainer means positioned in said three portions at said three locations to separate particulate matter from water being returned from said washing zone.
 5. The dishwashing machine of claim 1 wherein said drain means comprises: a first tubular member having inner and outer surfaces and having first and second apertures at longitudinally spaced locations along the wall thereof, a second tubular member having inner and outer surfaces and having a smaller outside diameter than said first tubular member and being mounted for rotation within said first tubular member, said inner surface defining an interior channel in said second tubular member, said second tubular member having third and fourth apertures in the wall thereof, said third and fourth apertures being spaced longitudinally from each other at a distance approximating the longitudinal separation of said first and second apertures and being angularly offset from each other in a circumferential direction relative to said second tubular member, first means placing the exterior of said valve in fluid communication with said interior channel, said first and second tubular members being rotatable relative to each other between a first position wherein said first aperture is placed in fluid communication with said third aperture and at least a second position wherein said second aperture is placed in fluid communication with said fourth aperture, third conduit means placing said first aperture in fluid communication with said first tank means, fourth conduit means placing said second aperture in fluid communication with said second tank means, and means for pumping fluid from said drain means to said washing zone.
 6. The dishwashing machine of claim 5 further comprising: seal means for preventing fluid leakage between said first and second apertures, said seal means being positioned between the inner surface of said first tubular member and the outer surface of said second tubular member and being positioned at least in part between said first and second apertures.
 7. The dishwashing machine of claim 6 wherein said seal means comprises: a first pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said third aperture, a second pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said third aperture and extending between and joining with said first pair of seal members to form a continuous seal around said third aperture, a third pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said fourth aperture, and a fourth pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said fourth aperture and extending between and joining with said third pair of seal members to form a continuous seal around said fourth aperture.
 8. The dishwashing machine of claim 5 wherein one end of said second tubular member is closed and wherein said first means comprises an opening in the opposite end of said second tubular member.
 9. The dishwashing machine of claim 8 further comprising: drive means coupled to said one end of said second tubular member for rotating said second tubular member between said first and second positions, said first tubular member being stationary relative to said second tubular member.
 10. A valve comprising: a first tubular member having inner and outer surfaces and having first and second apertures at longitudinally spaced locations along the wall thereof, a second tubular member having inner and outer surfaces and having a smaller outside diameter than said first tubular member and being mounted for rotation within said first tubular member, said inner surface defining an interior channel in said second tubular member, said second tubular member having third and fourth apertures in the wall thereof, said third and fourth apertures being spaced longitudinally from each other at a distance approximating the longitudinal separation of said first and second apertures and being angularly offset from each other in a circumferential direction relative to said second tubular member, and first means placing the exterior of said valve in fluid communication with said interior channel, said first and second tubular members being rotatable relative to each between a first position wherein said first aperture is placed in fluid communication with said third aperture and at least a second position wherein said second aperture is placed in fluid communication with said fourth aperture.
 11. The valve of claim 10, further comprising: seal means for preventing fluid leakage between said first and second apertures, said seal means being positioned between the inner surface of said first tubular member and the outer surface of said second tubular member and being positioned at least in part between said first and second apertures.
 12. The valve of claim 11 wherein said seal means comprises: a first pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said third aperture and a second pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said third aperture and extending between and joining with said first pair of seal members to form a continuous seal around said third aperture, and a third pair of seal members being positioned at least partly around the circumference of the outer wall of said second tubular member and being positioned on respectively opposite sides of said fourth aperture and a fourth pair of seal members positioned along the outer wall of said second tubular member on respectively opposite sides of said fourth aperture and extending between and joining with said third pair of seal members to form a continuous seal around said fourth aperture.
 13. The valve of claim 10 wherein one end of said second tubular member is closed and wherein said first means comprises an opening in the opposite end of said second tubular member.
 14. The valve of claim 13 further comprising: drive means coupled to said one end of said second tubular member for rotating said second tubular member between said first and second positions, said first tubular member being stationary relative to said second tubular member. 